What are the initial assessment and management steps for an adult with suspected sepsis, including criteria for suspicion, source control, empiric broad‑spectrum antibiotics, fluid resuscitation, vasopressor use, and lactate monitoring?

Sepsis: Initial Assessment and Management

Immediate Recognition and Risk Stratification

Recognize sepsis as a medical emergency requiring immediate action within the first hour of identification. 1

• Use NEWS2 score ≥5 to identify suspected sepsis in adults with confirmed or suspected infection; a score ≥7 indicates high risk requiring intervention within 1 hour, while a score of 5–6 indicates moderate risk requiring intervention within 3 hours. 2, 3
• Suspect sepsis in any patient with infection plus abnormal vital signs (heart rate >90 bpm, respiratory rate >22/min, systolic BP ≤100 mmHg), altered mental status, or evidence of end-organ dysfunction (oliguria, elevated lactate, hypoxemia). 1, 4, 5
• Override scoring systems and act immediately if critical features are present: mottled or ashen skin, non-blanching rash, cyanosis, capillary refill >2 seconds, or altered consciousness. 6

The Hour-1 Bundle: Five Critical Actions

1. Measure Lactate Immediately

• Obtain serum lactate at the moment of sepsis recognition as a marker of tissue hypoperfusion; lactate >2 mmol/L indicates significant hypoperfusion and lactate >4 mmol/L defines severe shock. 1, 6
• Repeat lactate within 2–6 hours if initially elevated, targeting normalization (<2 mmol/L) as a resuscitation endpoint. 1, 3
• Delayed lactate measurement is associated with increased mortality; patients with lactate >2 mmol/L show increased odds of death with each hour of delay (OR 1.02 per hour). 7

2. Obtain Blood Cultures Before Antibiotics

• Draw at least two sets of blood cultures (one aerobic and one anaerobic bottle per set) before starting antimicrobials—one set percutaneously and one through any vascular access device in place >48 hours. 1, 3, 6
• Never delay antibiotics beyond 45 minutes waiting for cultures; if venous access is difficult, start antibiotics via intraosseous or intramuscular route rather than postponing therapy. 1, 3
• Obtain cultures from other suspected sources (urine, sputum, wound, cerebrospinal fluid) as clinically indicated. 1, 6

3. Administer Broad-Spectrum IV Antibiotics Within 1 Hour

Give intravenous broad-spectrum antibiotics within 60 minutes of sepsis recognition; each hour of delay decreases survival by approximately 7.6%. 1, 3, 6

• Cover all likely pathogens with empiric therapy: gram-positive organisms (including MRSA when risk factors exist), gram-negative bacteria (including Pseudomonas in healthcare-associated infections), and anaerobes for intra-abdominal or aspiration sources. 1, 3
• Start an extended-spectrum β-lactam (piperacillin-tazobactam, cefepime, or meropenem) as first-line therapy in patients without known allergies or recent culture data. 3
• Add empiric antifungal coverage (echinocandin) in immunosuppressed patients, those with prolonged ICU stay, total parenteral nutrition, or recent broad-spectrum antibiotic exposure. 1, 3
• Reassess antimicrobial therapy daily once culture results are available, de-escalating to the most appropriate single agent within 3–5 days based on susceptibilities and clinical improvement. 1, 3

4. Rapid Fluid Resuscitation

• Administer at least 30 mL/kg of IV crystalloid (normal saline or balanced solution) within the first 3 hours of sepsis-induced hypoperfusion (hypotension or lactate ≥4 mmol/L). 1, 3, 6
• Give initial 500 mL boluses rapidly over 5–10 minutes, reassessing hemodynamics after each bolus using dynamic indices (pulse pressure variation, stroke volume variation) or static variables (blood pressure, heart rate, urine output, capillary refill, mental status). 1, 3
• Monitor for fluid overload by assessing jugular venous pressure, respiratory rate, oxygen saturation, and lung auscultation; reduce or stop fluids if signs of overload appear. 1, 3

5. Initiate Vasopressors for Persistent Hypotension

• Start norepinephrine as the first-line vasopressor at 0.05–0.1 µg/kg/min when MAP remains <65 mmHg after the initial 30 mL/kg fluid bolus, titrating to maintain MAP ≥65 mmHg. 1, 3, 6
• Peripheral administration of norepinephrine is acceptable initially to avoid delays while obtaining central venous access. 1
• Add vasopressin 0.03 U/min to norepinephrine when additional MAP support is needed or to reduce norepinephrine dose; vasopressin should never be used as the sole initial vasopressor. 1, 3
• Introduce epinephrine as a third-line agent if MAP targets remain unmet despite norepinephrine plus vasopressin. 1, 3

Hemodynamic Targets (First 6 Hours)

• Maintain MAP ≥65 mmHg in most adults; consider higher targets (70–85 mmHg) for patients with chronic hypertension whose autoregulatory curve is shifted rightward. 1, 3
• Target urine output ≥0.5 mL/kg/hour as a bedside marker of adequate renal perfusion. 1, 3
• Aim for central venous pressure (CVP) 8–12 mmHg (or 12–15 mmHg if mechanically ventilated) to assess fluid responsiveness. 1, 3
• Achieve central venous oxygen saturation (ScvO₂) ≥70% (or mixed venous O₂ saturation ≥65%) to confirm sufficient tissue oxygen delivery. 1, 3
• Ensure capillary refill <2 seconds, warm extremities, normal mental status, and palpable peripheral pulses as additional perfusion endpoints. 1, 3

Source Control (Within 12 Hours)

• Identify or exclude a specific anatomic infection source requiring emergent intervention (abscess, infected device, bowel perforation, necrotizing soft tissue infection) within 12 hours of sepsis onset. 1, 3, 6
• Perform definitive source-control procedures (drainage, debridement, removal of infected devices) as soon as medically and logistically feasible; inadequate source control is independently associated with increased mortality. 1, 3
• Use the least physiologically invasive effective method (percutaneous drainage rather than open surgery when appropriate). 1, 3
• Obtain prompt imaging (chest X-ray, abdominal ultrasound or CT, bedside point-of-care ultrasound) to confirm the suspected infection source. 6

Common Infection Sources to Evaluate

• Respiratory tract (pneumonia)—most common source; obtain chest X-ray immediately. 6, 4, 5
• Urinary tract (pyelonephritis, complicated UTI)—obtain urinalysis and urine culture. 6, 5
• Intra-abdominal (appendicitis, cholecystitis, peritonitis, diverticulitis)—perform abdominal imaging. 6, 5
• Skin and soft tissue (cellulitis, necrotizing fasciitis, abscess)—inspect for typical signs and culture if needed. 6, 5
• Bloodstream (catheter-related, endocarditis)—obtain multiple blood cultures and consider echocardiography when suspicion is high. 6, 5
• Central nervous system (meningitis, encephalitis)—assess for meningeal signs and perform lumbar puncture if no contraindications. 6, 5

Ongoing Monitoring and Reassessment

• Reassess the patient frequently (every 30 minutes for high-risk patients, every hour for moderate-risk) to evaluate response to treatment and need for escalation of care. 1, 6
• Monitor serial lactate every 2–6 hours if initially elevated, using lactate trend toward normalization to guide ongoing resuscitation. 1, 3
• Assess clinical perfusion markers continuously: mental status, urine output, skin temperature and mottling, capillary refill, and peripheral pulses. 1, 3

Common Pitfalls to Avoid

• Do not delay antibiotics: each hour of postponement lowers survival by ~7.6%; the delay should not exceed 45 minutes after cultures are drawn. 1, 3, 6
• Do not under-resuscitate: ensure the full 30 mL/kg crystalloid is given within the first 3 hours, but monitor for fluid overload. 1, 3
• Do not postpone vasopressors: initiate norepinephrine promptly if MAP remains <65 mmHg after adequate fluids; peripheral administration is acceptable initially. 1, 3
• Do not rely solely on MAP: normal MAP can coexist with severe tissue hypoperfusion ("cold shock"); assess lactate, urine output, mental status, and skin perfusion. 1
• Do not overlook occult infection sites: systematically examine for hidden sources such as perineal abscesses, retained foreign bodies, pressure ulcers, or spinal epidural abscess. 6, 5
• Do not use qSOFA alone to diagnose sepsis: qSOFA has poor sensitivity (31–50%) and should not delay treatment; it is a screening tool, not a diagnostic criterion. 3